Snubber



. June 3, 1930. L. BLACKMORE SNUBBER Filed July 29. 1927 III/Ill.

lia-tented -.lune 3, 1930 UNrrsD STATES PATENT OFFICE LLOYD BLACKMORE, OIE' HIGHLAND PARK, Ir'IIOHIG-AN, ASSIGNOR TO GENERAL MOTORS CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE SNUBBER Application led July 29,

This invention relates to spring suspensions for vehicles, and has particular reference to a means for` absorbing the road shocks.

Prior constructions have usually made use of a separate shock absorbing means which have customarily been placed at the axle between the spring and the frame. It is the purpose of the present invention to incorporate a shock absorber within the spring l@ shackle at one end of the spring and thereby eliminate the usual shock absorber.

To accomplish the object of the invention I make use of a bracket which is pivoted to the vehicle frame and through which there extends one end of the spring. Friction surfaces are built into the bracket above and below the spring and are in directfcontact therewith. Oneof the friction surfaces is stationary, while the second is movable, and

the arrangement of these friction surfaces is such that they will allow for a substantially free movement of the spring in one direction and offer substantial opposition to the movement in the opposite direction. The

stationary friction surface is fixed to the bracket while the .movable one is attached to a member confined within the bracket and capable of movement relative thereto. The bracket and movable member have co-operating cam surfaces which will permit the member to slide over the bracket to permit substantially free movement of the spring in the one direction. A coil spring is arranged between the bracket and movable member,

. and constantly tends to urge it against the vehicle spring, and as the vehicle spring tends to move in the opposite direction, the twor Vfriction surfaces willbe urged toward each other and tend. to obtain a firmer hold on the Y spring and resist ,its movement. The vehicle spring will therefore be forcedy through the bracket against the resistance of the two friction surfaces, thereby retarding the movement of the spring and preventing vio lent rebound.

.This retarding movement-on the rebound Vwill befmost effective when the spring flexure ,is the greatest for thereason that the spring has a-toggle-like action as it vibrates or oscillatesin its vertical plane. vThe point of ap- Figure 2fis an enlarged longitudinal sec- 1927. Serial No. 209,313.

plication of the force may be considered as at the axle and when the spring is bowed to its maximum, the arms of the toggle, i. e. the two spring halves at either side of the axle, are more nearly in vertical alignment with the point of force application. In this situation a relatively much greater force is required to return the spring to normal position, for when the spring flexure is small, the toggle arms are almost in alignment and are capable of exerting a relatively greater force at the spring ends. This capability of using the inherent force action of a toggle joint is an essential part of the invention for the reason that it is available when most needed. Thus; when the spring fiexure is large, the force applied to force the spring end through the bracket and against the resistance offered by the friction surface will be greater, and longer`- in action, and necessarily cause a greater and firmer gripping of the spring end between the friction surfaces. The advantage will also be with the friction surfaces because of the extreme position of the toggle arms. The check onthe recoil or rebound will therefore begreatest at the position of maximum spring flexure or major deflections, and least with minimum llexure or minor deflections, an accomplishment which is the aim of all shock absorbers. When the spring flexure is small, the friction surfaces offer no essential retarding effect to the spring end'because the toggle arms or spring halves are in substantial alignment and capable of exercising a very great force. During small oscillations, therefore, the spring will tester or oscillate up and down substantially unobstructed, or in the manner of the conventional spring suspension.

The invention is ydisclosed on the accom panying drawing in which:

Figure l shows a side view of a portion of the frame of a vehicle with my invention appliedv thereto.

tional detail of the novel bracket.Y

Figures 3 and 4 are sections on the lines 3 3 andk 4-4 of Figure 2.

Referring to the numbered partson the drawing, l0 indicates the frame or chassis 100 f described.

of a vehicle, 14 the axle, and 12 the spring comprising the two halves V11 and 13. The spring is pivoted in the usual way at the one end as shown at 16 while theother end is connected to the Vframe by means of the bracket 18 pivoted at 20 to a second bracket 22 secured Vto the frame. The lpivot 20 may be at the center or either end of the bracket.

The spring 12 in Figure 1 is shown as substantiallyL flat which is its normal condition or the position-of laminated springs'in use on vehicles of present practice. The halves .11. and 13 are thus free to react to any slight oscillations which will afford even riding over small bumps or ruts in the road, or'such unevennesses as l are ordinarily metl with. However, when passing over relatively deep ruts or large bumps in the road, the spring 12 will be deeply arched which will position the spring halves 11 and 13 more kto the vertical so' that the return movement of the aXle 14 will force the .spring end 13 to slide i through the bracket 18 and against the pressure of two friction surfaces as will be later The bracket 18 is formed of two complementary halves 24 and 26, each bracket half having eyes 28 and 30 which cro-operate with an eye 21 on the bracket 22 to form a pivotal connection as shown at 32.

At Vthe upper portion of the bracket halves there vis-confined the U-shaped member 34,V

secured by means of bolts 36 passing through bracket 18. lNuts 38 are applied tothe ends of the bolts 36 to holdthe parts together.

To the web portion 37 of the Ulshaped member 34 there is secured by means of the rivets 40 a suitable friction fabric 42 which engages the upper surface of the springend 44, which passes through the bracket 18 as is seen from Figure 2. f

In thelower portion of thebracket 18 there is mounted thermovable member 46 comprising a Aplatef48 and a cam 50, and attached to the'platei48 by means of the rivets 54:

is a second friction fabric 52.` These rivets also form the means of connecting the Acam 50 tothe plate 48. The frictionmaterial 52 con` tactsr` withvthe lower side of the spring end 44 and is constantly urged thereagainst by means of the coil spring 56 acting on the cam 50 which co-operates the cam surface 58 on the bracket 18. The` spring 56 is confined between a shoulder 60 on the cam 50, anda 'v washer'62resting on a shoulderlfo'ri'nedy on a bolt Get-which is' threaded into the bracket 18- as shown at 66.1, The shank 65 of the bolt 64 isofvreduced diameter and extends through the coil spring 56,-an'd through an'ope'mng 68 in the shoulderO of the cam 50 and holds the spring-inposition;

l The base lof theU-shaped member 34 and the plate 48 are separateda greater `distance at the front end than at therear end as shown at 51'in Figure '2. Thepurpose of this construction is to allow for an easy movement of the spring end 44 toward the left or when. the vehicle spring 12 is flexing. On the rebound, or when the spring 12 is returning toV its normal state, the spring 56 and the cam surfaces() and v58 will urge the friction material 52 tighter against the spring 44, causing a firmer grip and a retarding of the return movement or action of the spring and thereby vpreventingviolent rebound.l The spacing of Vthe member 56 is capable-ofmoving as a whole to theleft against the tension of the y coil springVV 56 as shown lat Figure 2. However'on the rebound, or as the spring tends to return to the position shown at Figure 1, the t coil spring 56 will urge-the member 46 and the Yfriction material 52upwardly and against the spring end 44,- causing a firmer grip between Ythe spring and friction surfaces and tend to confine the spring end between'the i? two'fabric surfaces 42 and 52. The faster the .spring end 44 tends to force-'its Way through' the bracket 18, all the, more will the friction surfaces ofthe fabrics 42and 52 tend to ob-k tainaiirmer grip, andV resist thepassage ofthe springthrough the bracket. This free movement of the vehicle springin the one direction, and the resistanceto its movementl I on the rebound will prevent violent rebound in accordance with the principles set ,out in f thestatement of invention'. f 1

f'fThe spring`12 is, of course, Capable of being 'Y Hexed to Vanarclied'or a bowed position either y aboveor-below its normally straight position. f Y f :io g

The resistance to the return of the spring to normal Vposition .is the saine Whetherthe spring is arched or bowed above or `below its normal position.

Iclaim: 'V ,Y 'v 1. In a shock absorberfor"vehicles, a norl-r mally substantially straight lspriiig .pivoted at one end' tothe vehicle frame Vand adapted V i: 'I `to'be flexedtoarched orbowed positions atq.

both .sides of.r itsk normal position, aV bracket pivotedV to the 'frame 'and 'directly connected .v

to `the' other end of the spring, vand av plu'y Y rality of friction surfaces in said bracket for mal position.

I 2. In a shock absorberfor vehicles, a nor-` retardingreturn movement of said spring from bowed position on either side of its normally substantially straight spring adapted fr to bevilexed to arched or bowed positions at bothsides vof itsfnormal position and permanentlylpivoted at one end to the vehicle a bracket attached to the vehicle for receiving one end of the spring,a friction material secured to the bracket and engaging the spring, a movable member confined in the bracket, and a friction material secured to the member and bearing on said spring, said friction material resisting return movement of said spring from bowed position on either side of its normal position.

8. In a shock absorber for vehicles, a two part bracket pivoted to the vehicle, a spring having an end passing freely through the bracket, a U-sliaped member secured in said bracket, a friction material secured to said member and bearing on said spring, a movable element confined within said bracket, a

f friction material secured to said element and bearing against said spring, co-operating cam surfaces on said element and bracket, and means tending -to urge said element against said spring.

4f. The invention 0f claim 3, said means comprising a resilient member secured between said bracket and movable member.

5. The invention of claim 3, said means comprising a bolt secured in the bracket andy passing through an opening in the movable member, and a spring surrounding said bolt and conned between the bracket and movable member.

6. In a spring suspension for vehicles, a fiat spring having one end permanently connected and its other end slidably connected to the vehicle frame, means in said slidable connection for retarding rebounds of said spring due to major deflections but offering no substantial resistance to rebounds due to minor deflections. f

7. The invention of claim 6, said means comprising apluralityof friction surfaces at said bracket.

8. In a shock absorber for vehicles, a noi'- mally substantially straight spring adapted to be flexed to arched or bowed positions at both sides of its normal position and pivoted at one end to the vehicle, a bracket attached to the vehicle for receiving one end of tlie spring, a friction material securedA to the Y bracket and engaging the spring, a movable member'confined iii the bracket, a friction material secured to the member and bearing on said spring, said friction'inaterial resisting return movement of said spring from Vbowed position on either'side of its normal position, and means for urging said member' against said spring..

9. In a shock absorber for vehicles, a nor'- mally substantially straight spring adapted to be iieXed to arched or bowed positions at both sides of its normal position and pivoted at one end to the vehicle, a bracket attached to the vehicle for receiving one end of the spring, a friction material secured to the bracket and engaging the' spring, a movable member confined in the bracket, a friction material secured to the member and bearing on said spring, said friction material resist-V bowed position on either side of its normal position, and a resilient element for urging said member against said spring.

10. In a shock absorber for vehicles, a normally substantially straight spring adapted to be flexed to arched or bowed positions at both sides of its normal position and pivoted at one end to the vehicle, a bracket attached to the vehicle for receiving one endof the spring, a friction material secured to the bracket and engaging the spring, a movable member confined in the bracket, a friction material secured to the member and bearing on said spring, said friction material resisting return movement of said spring from bowed position on either side of its normal position, and a sprino confined between said bracket and member for urging said member toward said spring. f

l1. In a shock absorber for vehicles, a spring, a bracket attached to the vehicle for receiving one end of the spring, a friction material secured to the bracket and engaging the spring, a movable member confined in the bracket, a friction material secured to the member and bearing on said spring, said friction material resisting movement of said spring in one direction, a cam surface on said bracket, a ,cooperating cam surface on said member, and means urging said member over said cam surface to cause the friction material to engage the spring.

l2. In a shock absorber for vehicles, a spring, a bracket attached to the vehicle for receiving one end of the spring, said bracket comprising two complementary parts having an ear forming a pivotal connection with the vehicle frame, a friction material secured to the bracket and engaging the spring, a movable member confined in the bracket, and a friction material secured to the member and bearing on said spring, said friction material resisting movement of said spring in one direction.

13. In a shock absorber for vehicles, a spring, a bracket comprising two complementary halves attached to the vehicle for receiving one end of the spring, a friction material secured to the bracket and engaging the spring, a U-shaped member secured in said `bracket and serving as a backing for said friction material, a movable member confined in the bracket, and a friction material secured tothe member and bearing on said spring, said friction material resisting movement of said spring in one direction.

' 14. In a shock absorber for vehicles, a normally substantially straight spring adapted to be flexed to arched or bowed positions at both sides of its normal position and perinanently pivoted at one end to the vehicle, a

connection at the other spring end between ing return movement of said spring from j connection in a direction longitudinally kof Y the spring and vehicle allowing relative movementbetween the spring and 'oonnee- A tion in a direction long igitudinallyof the spring, and meansin said Connection forresisting returnrmovements of the spring from its bowed positions on either side mal position. y Y

15. In ak spring suspension orvehioles, a normally substantially straight v spring adapted to be ileXed to arched or bowed positions at both sides of its normal position and permanently pivoted at one end to the vehicle, and a Connectionr at the other spring end between the spring and vehicle allowing relative movement between the spring land the spring to allow the return of the spring from bowed positions on either side of its normal position.. v

16. In a shook absorber for vehicles, a spring adapted to be flexed to bowed vposi` tions at both sides of its normal position and permanently pivoted atone end to the vehiele, a connection at the other spring end between the spring and vehicle allowing relatively unrestrained movement between the spring and connection in a direction longitudinally of the spring, and means in said oonneotion for resisting return movements of' the spring from its bowed positions on either side of its normal position.

In testimony whereof I aflix my signature.

LLOYD BLAGKMORE.-

menes 

